Pulper



Patented Sept. 23, 1924.

UNITED STATES ANDREAS BIFFAR, OF MILTENBERG, GERMANY.

IP'ULPER.

Application filed August 22, 1921. Serial No. 494,140.

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT.

To all whomv it may concern:

Be it known that I, ANDREAS- Brrrnn, a citizen of the German Empire, residing at Miltenberg, Germany, have invented certain new and useful Improvements in Pulpers (for which 1 have filed application in Germany, March 19, 1917), of which the following is a specification.

My invention relates to pulpers employed in paper manufacture. In pulpers as here tofore constructed and in wl ich the pulp has to travel a comparatively long way, it is a serious drawback that the speed of the upper layers of the pulp is greater than that of the lower layers. It thus frequently happens that portions of the pulp are deposited upon the bottom and the sides of the engine and aggregate there. Subsequently pieces or larger lumps become detached from 0 time to time and mix with the pulp refined by repeated grinding.

The pulp finished in such pulpers thus in spite of repeated grindings remains uneven in quality and cannot be employed for the manufacture of superior kinds of paper, especially paper used for spinning purposes.

The object of this invention is to avoid these drawbacks by providing a trough divided by longitudinal partitions into three channels with a grinding mill at each end, by means of which the pulp is ground, raised to a certain height and positively circulated under a steep angle of flow.

In the drawings affixed to this specification and forming part thereof a pulper embodying my invention is illustrated by way of example. In the drawings- Fig. 1 is a sectional side-elevation, and

Fig. 2 a sectional plan.

Referring to the drawings the trough o is longitudinally divided into three compartments (Z, 6, f by the partitions b and c, which compartments are open at both ends and communicate with the grinding mills g, in. The compartments or channels have steeply inclined bottoms, the bottom in the middle channel 6 sloping from the front to the back and the bottoms of the two outer channels (5, f on the other hand from the back to the front. The pulp charged into the trough thus flows first to the grinding mills g, h. During the rotation of the grinding mills the pulp is reduced and raised up to the height of the top of the return channels. In the example illustrated the pulp is conveyed into the channel 6 by the grinding mill 9 and into the channels 0?, f by the grinding mill 71. From the highest points of the troughs the pulp flows into the grinding mill arranged at the opposite low ends of the troughs.

Inasmuch as the circulation channels have a very steep gradient and the grinding mills exert a sucking action, the entire stream of pulp is obliged to move uniformly and quickly, so that the pulp cannot deposit and aggregate in any parts of the trough.

lhe grinding mill 71- consists of a knifecylinder, while the grinding mill g is constructed for finer reduction and comprises grind-stones, the counter-stones being adapted to be adjusted with respect to the runner from the outside. The pulp enters. the finemill axially from opposite sides, so that it does not exert a pushing action upon the driving shaft. This allows the driving shaft of the mill to be directly coupled with and to be driven from an GlGCfIO-HlOtOl.

The motion of the driving shaft of the fine-grinding mill may be transmitted by a belt and pulleys of equal diameters to the other grinding mill.

1 claim:

1. In a pulper in combination, three channels extending substantially in parallel to one another and having a steep gradient and grinding device disposed at each end of said channels in such manner as to raise the pulp to the highest points of the channel bottoms and means for introducing the pulp into one of said grinding devices in axial direction.

2. In a pulper in combination, three channels extending substantially in parallel to one another and having a steep gradient and a grinding device disposed at each end of said channels in such manner as to raise the pulp to the highest points of the channel bottoms, one of said grinding devices comprising grind stones, and means for introducing the pulp into one of said grinding devices in axial direction.

In testimony whereof I afiix my signature.

' ANDREAS BIFFAR. 

